11 - Spatio-Temporal Extents

Abstract

This chapter focuses on spatio-temporal extents and describes some of the basic kinds of spatio-temporal extents that are commonly found. It examines the space-time patterns that different kinds of spatio-temporal extents exhibit. The most important relationship between spatio-temporal extents is that of one being part of another. This is called aggregation when the whole is the sum of the parts. An aggregation is a relationship where one spatio-temporal extent is a part of another such that the whole is the sum of the parts. This key relationship is also examined in the chapter. Sometimes, the whole is more than the sum of its parts. The parts compose something that has emergent properties that result from the way that the parts are arranged. This is called composition. A composition is an aggregation where the parts are arranged in such a way that the whole is more than the sum of the parts. Finally, there is the case where the part is the full spatial extent for a period in the; that is, the part is a state of the whole. This is termed temporal composition. A spatio-temporal extent may be part of one or more other spatio-temporal extents.